Rare earth elements often serve as catalysts for the redox reaction between oxygen (O-2) and the target gas. In particular, the Ce doping can contribute effectively to the humidity resistance of the sensors due to the Ce3 + ions. Unfortunately, the Ce doping often results in a low enhancement of the sensor response. In this work, Pd, Ce co-doped indium oxide (Pd/Ce-In2O3) nanofibers were designed and prepared via the traditional electrospinning technique. Results showed that Pd/Ce co-doping created more oxygen vacancies and smaller grains within the In2O3 skeletons. As expected, H-2 sensing tests indicated the Pd/Ce-In2O3 sensor shows the maximum response value of 41.13-10 ppm hydrogen at 280 degrees C, approximately 1.85 and 4.27 times those of the Pd-In2O3 and Ce-In2O3 ones, respectively. Even at 80 degrees C, this sensor still shows a response of 1.85. More interestingly, the Pd/Ce-In2O3 sensor also shows fast response/recovery rates (< 1 s / 5 s), excellent gas selectivity, and high long-term stability, as well as excellent anti-humidity properties. In addition, further analysis of the gas sensing enhancement mechanism indicates that the orbit hybridization of Ce (f) and Pd (d) not only increases the adsorption property of In2O3 to H-2, which primarily contributes to the response, but also enhances the catalytic property of Pd/Ce composites and the transfer of sensing electrons from the catalyst to In2O3 matrix, benefiting the response value, response speed and humidity resistance of the sensors.

The effects of 212-MeV Ge ion irradiation on the electrical performance of the vertical beta-Ga2O3 Schottky barrier diode (SBD) devices have been investigated in this work. With a fluence of 1x108ions/cm(2), it is found that the electrical performance of the vertical beta-Ga2O3SBD is significantly changed, including a decrease in the effective carrier concentration (ND) from 8.82x1015to2.64x1015cm(-3), a reduction in reverse current density(JR) from 1.39x10-6to 1.17x10-7A/cm(2), a restoration of the forward current density (JF) and series resistance(RS), and an increase in the reverse breakdown voltage (BV)from 218 to 420 V. Deep-level transient spectroscopy (DLTS)analysis reveals a decrease in the asymmetric defect peakatEC-0.78 eV in the virgin sample, accompanied by the appearance of theEC-0.84 eV defect peak in the irradiated sample. This indicates that Ge ion irradiation can mod-ify the arrangement of defect levels and interface states(NSS), consequently leading to reshaping the distribution of asymmetric defect peaks. Additionally, technology computer-aided design (TCAD) simulations demonstrate that the weakening of the metal-semiconductor (M-S)interface state, enhanced mobility, and the presence of deep-level defects in the bulk material together contribute to alter the electrical properties of the device postirradiation. Therefore, the low-fluence Ge ion irradiation can optimize the Au/Ni/ beta-Ga2O3 interface and improve the electrical performance of the vertical beta-Ga2O3SBD

In this work, the electron irradiation effects and post-irradiation annealing (PIA) response on SiC MOSFETs were investigated and analyzed in terms of the evolution of oxide- and interface-trap charges after irradiation and PIA. It is found that the electron irradiation leads to the significant decrease of Ron, degraded blocking characteristics, and negative shift of capacitance characteristics, which can be ascribed to the promoted generation of positively charged oxide and interface traps by irradiation. Interestingly, these degraded electrical properties can be partly or completely recovered by room-temperature (RT) anneal, which is associated with the difference in the sensitivity to the oxide/interface charge variations in the channel, JFET, and termination region. Surprisingly, the positive charge in the oxide presents an incomplete recovery, which is suggested to result from the tunneling electrons from SiC and thus the subsequent electron capture by positively charged oxygen vacancy in the oxide. Whereas, the irradiation-induced interface-trap charges are fully eliminated even after RT anneal for 15 days. Deep-Level Transient Spectroscopy (DLTS) characterizations shows that the interface defects with the energy band from EC − 0.14 eV to EC − 0.7 eV are enhanced by irradiation and exhibits similar dependence on the filling pulse as the near-interface traps. However, the irradiation-induced interface state density (Dit) distributions show a recovery behavior after RT storage, which is suggested to be resulted from the change in the charge states of interface defects from the electron trapping.

Considering the future applications of the ultra-wide bandgap semiconductor β-Ga2O3 in high-performance electronic devices and aerospace, the effects of low fluence 212 MeV Ge swift heavy ion (SHI) irradiation on the structural and optical properties of β-Ga2O3 epitaxial layers have been studied in this work. The alternations in Raman scattering properties of the epitaxial layer after Ge SHI irradiation indicate the generation of lattice defects. The increased concentration of oxygen vacancies after irradiation leading to an enhanced area ratio of the yellow-red emission band in the PL spectrum of the β-Ga2O3 epitaxial layer. Simultaneously, the PL intensity quenches as the irradiation fluence increases, attributed to the generation of non-radiative recombination centers. Furthermore, HRTEM analysis provides direct evidence of lattice damage caused by 212 MeV Ge SHI irradiation to the samples. The results demonstrate that the spectral behaviors of β-Ga2O3 epitaxial layers can be modulated by low fluence Ge SHI irradiation with less damage caused to the overall crystalline quality and structure.

The evolution of deep levels in n-type 4H-SiC Schottky barrier diodes (SBDs) irradiated with 9.5 MeV/u 209 Bi ions at room temperature was investigated by Deep Level Transient Spectroscopy (DLTS). DLTS scans from 40 K to 800 K indicated the presence of EN1, EH Ti(h) (EC-0.13(1) eV), EH 1 ( E C-0.48(2) eV), EH4 (EC-0.97(3)eV), and EH 6/7 (EC- 1.60(1) eV) defects levels within the energy range from 0.12 to 1.6 eV below the conduction band edge (EC). The DLTS results for the 4H-SiC SBD samples before and after irradiation clearly demonstrated that swift heavy ion (SHI) irradiation induced the evolution of deep level defects or defect states in 4H-SiC SBD device. Notably, at a fluence of 1 x 1011 ions/cm2, the ion-induced deep level defects or defect states exhibited significant recovery due to the cumulative effect of heat, leading to SiC re-crystallization.

The single-event leakage current (SELC) mechanism of the silicon carbide (SiC) junction barrier Schottky (JBS) diode is thoroughly investigated in this work. A comprehensive physical model to quantify the degree of SELC for the JBS diode is also proposed. From the collected experimental results, it is found that the leakage current of the SiC JBS diode increased with the increase in both the reverse bias voltage under irradiation and the total fluence. According to the results of the current response during irradiation and the emission microscope (EMMI) after irradiation, it can be inferred that the leakage current degradation of the samples originated from the accumulation of the Schottky junction's area with a barrier reduction by the ion-induced local high temperature. Taking the degradation mechanism into account, a novel physical model is developed with the help of TCAD simulations. This model clearly highlights the relationship between the degradation (i.e., Schottky barrier height reduction and amplification of the leakage current) and the irradiation conditions (i.e., reverse bias voltage and fluence). This work provides valuable insights into the underlying origins of the SELC effect and its potential mitigation in SiC JBS diodes.

The influence of the annealing treatment on the performance of commercial 4H-SiC Schottky barrier diodes (SBDs) subjected to heavy ion irradiation under room temperature (RT) and low temperature (LT) are presented. Experimental results confirm that annealing treatment effectively eliminates defects and interface states caused by heavy ion irradiation, particularly for 4H-SiC SBD under LT irradiation. Increasing the annealing temperature leads to the slight improvement in forward current, leakage current and breakdown voltage. However, the annealing process may result in the formation of Ti and Si compounds at the interface between the Schottky metal and SiC, as well as a significant number of vacancies. Combined with Technology Computer Aided Design (TCAD) simulations, it is concluded that the interface trap charge concentrations exceeding 1 x 1012 12 cm-2 significantly impact the breakdown characteristics of 4H-SiC SBDs.

Post oxidation annealing (POA) is a crucial technique for enhancing the performance of SiC metal-oxide-semiconductor field effect transistors (MOSFETs). This study investigates the impact of nitrogen-based POA on the 4H-SiC/SiO2 interface, utilizing x-ray photoelectron spectroscopy to assess changes in stoichiometry and band alignment. We discovered that high-temperature nitrogen POA significantly refines the interface quality, shifting the SiOxCy binding energy from 101.3 eV (at 400 degrees C) to 102.1 eV (at 1150 degrees C) and reducing the C:Si ratio from 1.120 (at 400 degrees C) to 0.972 (at 1150 degrees C), indicating reoxidation and transition from C-rich interface to Si-rich interface. Despite improvements, the conduction band offset at the interface, decreases from 2.59 eV to 1.62 eV with increasing annealing temperature, suggesting a higher likelihood of electron tunneling. This finding underscores the necessity of evaluating band offsets introduced by POA to ensure the reliability of SiC MOSFETs. Additionally, excessive Ar ion etching introduces residual Ar and surface charges, causing band bending and an increased density of states in the valence band of the 4H-SiC substrate.

This paper proposes an efficient compensator of the cascaded integrator comb filter (CIC filter) to improve the passband droop. A compensator is separated into two stages and separately inserted into the CIC filter. The amplitude-frequency response of the proposed method is compared with other proposals in recent literature, and the comparison shows that the proposed method obtains flatter passband (less than 0.013 dB in the wideband case and less than 0.0003 dB in the narrowband case). The multiplierless implementation of the proposed method only introduces 15 adders and 7 registers, which ensures the low-complexity hardware structure.

A novel, trench gates, double reduced surface field, lateral insulated gate bipolar transistor based on silicon-on-insulator (SOI-LIGBT) is proposed and investigated. A p-top layer connected to the emitter via two series diodes and n-rings surrounding the bottom of trench gates are used to reduce the on-state voltage drop ( V CE(sat) ) and turn-off loss ( E off ). A deep trench with a p-ring is introduced to form a gate-drain shorted positive channel metal oxide semiconductor, which can automatically raise the potential of the p-ring during turn-off so as to enhance the dynamic avalanche immunity. Besides, the deep trench with a p-ring can shield the high electric field from n-rings at the blocking state, which avoids the breakdown of n-rings. Simulation results indicate that the proposed LIGBT can be safely turned off even under a bus voltage equal to the breakdown voltage ( V B ), and V CE(sat) under E off = 1 mJ cm −2 can be 24% lower than that of the conventional LIGBT.

The reliability issue of threshold voltage (V gs ( th ) ) still exists in Silicon carbide (SiC) based metal-oxide-semiconductor-field-effect-transistors (MOSFETs). In this paper, the threshold voltage instability of 4H-SiC MOSFET is deeply studied through Silvaco TCAD simulation. This work mainly investigates the instability (shift) of the V gs ( th ) affected by interface states (interface traps), near interface traps, and mobile ions. The results display that the effect of near interface traps on the V gs ( th ) shift is greater than that of interface traps. The electron capture ability is related to the energy level of the traps. With the energy level increasing, the V gs ( th ) shift increases firstly and then decreases. The peak energy level is related to the trap position and trap density. Furthermore, the effect of the mobile ions in the oxide layer on the V gs ( th ) shift is limited. However, when moving to the SiC/SiO 2 interface, they will greatly impact the V gs ( th ) and affect the device performance seriously.

This paper provides a new strategy to recover the threshold voltage of SIC MOSFET after gamma radiation by self-heating in circuit, where the half-bridge topology is adopted. The safe self-heating of the SIC MOSFET can be realized by operating at the short circuit mode with a low current. The circuit board for self-heating of SiC MOSFET is designed. An appropriate control setting is found by experiments. After one time of 2 ms safe self-heating with power consumption from 65 W to 360 W, the threshold voltage of SIC MOSFET after gamma radiation is found to be recovered by 0.23 V∼0.42 V, which is about 29%∼47% of threshold voltage reduction (0.78 V∼0.9 V) by gamma radiation. In addition, more times of safe self-heating can further recover the threshold voltage by 27% (i.e., 0.23 V).

The paper introduced the principle and structure of electronic sphygmomanometer DS-503, statistical analyzed its failure cause, and explained the fault handling. Finally, we carried out the quality control testing of electronic sphygmomanometer to ensure the accuracy and safety of clinical using.

Selective laser melting (SLM) can fabricate titanium and its alloy components with both elaborate internal architectures and complex shapes without geometric constrictions. The corrosion resistance of SLM-produced Ti and its alloy is crucial in some applications such as marine and biomedical environments. Here, potentiodynamic polarization and electrochemical impedance spectroscopy were used to evaluate the corrosion behaviors of SLM-produced Ti-6Al-4V in the four corrosive media (simulated body fluid (SBF), phosphate buffered saline solutions (PBS), 3.5 wt.% NaCl aqueous solution, 15 wt.% NaCl aqueous solution). The relevant results demonstrate the inferior corrosion resistance of the SLM-produced Ti-6Al-4V sheet compared with the commercial casting Ti-6Al-4V sheet in the four solutions. The corrosive current density of SLM-produced Ti-6Al-4V in PBS solution is 1.78 μA cm−2 and 7.065 μA cm−2 in 15 wt.% NaCl solution, and the values of charge transfer resistance for SLM-produced Ti-6Al-4V in the four solutions are in the order: 17.9 kΩ cm−2 (in 15 wt.% NaCl) < 25.2 kΩ cm−2 (in 3.5 wt.% NaCl) < 28.1 kΩ cm−2 (in SBF) < 39.8 kΩ cm−2 (in PBS), demonstrating the best protective performance of the passivation film on the SLM-produced Ti-6Al-4V sheet in PBS.

提出了一种基于双极型晶体管(BJT)宽温度范围的温度传感器.该温度传感器电路通过两个温度特性互补的电流产生一个高斜率的电压,采用电流增益补偿技术和斩波稳定技术来提高传感器输出电压的线性度,同时可通过合理调节电阻值和电流镜比例获得不同的输出电压.在0.18 pm HVCMOS工艺下对传感器进行仿真,结果表明,在-55～125℃的温度范围内,温度传感器的温度系数为11.2mV/℃,误差在-0.8～0.8℃.

针对高精度集成电路系统,工艺条件导致的误差需要通过修调弥补.基于0.18 μm CMOS工艺设计了一种针对片上基准源的修调电路,通过调整数字输入信号,对电阻网络修调电路进行控制,通过重配置输出级电阻比例,从而达到对基准源电压的调整.基准源采用改进的Neuteboom带隙电路,在5 V电源电压的工艺条件下进行仿真测试,在-40～125℃温度范围内,实现了 2.98×10-6/℃的温度系数.通过电阻网络修调的基准电压变化范围为2.3840～2.5154V,电压修调步长为2mV.

采用失重法和电化学方法,通过腐蚀形貌观测、腐蚀产物元素分析和物相分析研究了再生水中常见的大肠埃希氏菌(Escherichia coli,Eoil)对QT500-7球墨铸铁腐蚀行为的影响.失重腐蚀试验表明:含菌体系中铸铁的失重腐蚀速率高于无菌体系,并且随着腐蚀时间的延长,含菌体系与无菌体系腐蚀速率的比值持续增大,说明Eoil对铸铁的腐蚀具有明显的促进作用.电化学测试结果表明:试验周期内,含菌体系的自然腐蚀电位比无菌体系低,铸铁的腐蚀倾向更大.浸泡8 d后,含菌体系的腐蚀电流约是无菌体系的6倍,电荷转移电阻R ct约是无菌体系的1/10.电化学测试结果和失重腐蚀试验结果相吻合,在培养基中铸铁在Eoil影响下的腐蚀形态为点蚀.含菌体系的铸铁腐蚀产物中Fe元素和O元素的含量明显高于无菌体系,铸铁在含菌和无菌环境下的腐蚀产物主要成分均为Fe(OH)2和α?FeOOH,这说明Eoil加速了腐蚀的进程,但并未改变腐蚀的途径.

长期以来,学界对《简·爱》的分析主要集中在两方面,即《简·爱》作为"女性主义狂热崇拜"的文本和作为"殖民话语"的文本.简·爱作为父权制下的女性和作为英国殖民者的双重身份使其能与梅森和罗切斯特分别进行性别层面和种族层面的共谋.简·爱与梅森之间的种族差异削弱了性别层面的共谋,而简·爱与罗切斯特的婚姻则象征着意识形态的结合,同时暗示了种族共谋的胜利,《简·爱》的结局也是帝国主义时期种族主义的产物.

多极矩展开是一种重要的分析方法,由静态电磁场多极矩展开得到的电多极子和磁多极子是基础而重要的物理模型.多极矩展开表示方法、多极子模型与多极子以及电磁场相互作用是多极矩分析教学的核心内容.本文从上述三个方面展开探讨:给出静态电场和静态磁场的内部和外部多极展开;讨论多极矩展开的不同表示的关系;强调多极子是基于远源处电磁势对源进行的等效点源替代;最后,从受力与力矩方面考察电多极子和磁多极子与外电磁场的相互作用.

This paper presents an advanced topology of bandgap voltage reference (BGR) which consists of a novel curvature-compensated circuit and a current-mode trimming circuit. A positive-temperature-coefficient (positive-TC) nonlinear term is produced in the difference between the base-emitter voltages of two bipolar junction transistors (Δ V BE) to realize the high-order curvature compensation. The Δ V BE is generated by adding a negative-TC current into the bandgap core. Owing to the compensated Δ V BE, the BGR could be fine-tuned by an innovative current-mode trimming circuit which takes less area and achieves a larger trimming range. Benefiting from the trimming circuit, the PVT stabilities of proposed BGR are improved. Designed in a 0.18 μ m HVCMOS process, the BGR occupies an active area of 267 μ m × 226 μ m. The post-layout simulation results show the BGR reaches a low TC of 1.64 ppm/∘C in a wide range of -55 °C to 125 °C.